The present invention is directed toward a flexible bulk container and more particularly toward such a container which has a raised lifting hoop which can be engaged by a hook or by the forks of a forklift or the like. Furthermore, it is directed to a container which does not assume a tilted orientation but stays substantially upright when lifted.
Large, flexible fabric bags for containing and transporting granular or powdered bulk material have been used for many years and their use is becoming increasingly more popular. This is primarily due to their relatively low cost and to the fact that when the bags are empty they take up very little space and are relatively light.
When filled, the flexible bulk containers may carry a cubic meter or more of material and may weigh in excess of two tons. Straps are normally provided and are securely fastened to the bags adjacent the top thereof to form lifting loops which can cooperate with the forks of a forklift truck or other lifting device when it becomes necessary to transport a full bag. Containers of this type are shown, for example, in U.S. Pat. Nos. 4,010,784; 4,207,937; 4,300,608; 4,301,848; 4,499,599 and 4,573,204.
Prior art containers normally include straps or lifting loops which are secured to the bags adjacent the corners or edges thereof. When lifting these containers, it is necessary for the forks of the forklift to engage all of the lifting loops or, at the very minimum, loops at opposite corners. While it might be possible to lift a prior art bag utilizing only one of the lifting loops, this would cause the bag to tilt when lifted therefore making it difficult to place the bag down again. This is due to the fact that the tilted bag would tend to fall onto its side as it was being again lowered onto a flat surface.
In U.S. Pat. No. 821,177 to Leue, a sack having a plurality of flexible eyes arranged on its exterior and having a flexible hoop passing therethrough is disclosed. This arrangement was developed for closing the sack and not for lifting the same. However, if used for lifting the sack, the positioning of the hoop below the top of the sack along with the large number of eyelets prevents the bag from maintaining a non-tilted orientation if lifted via the hoop. Similarly, the positioning of the strap below the top prevents the bag from being lifted by a lifting mechanism without manual alignment.
The prior art does disclose self-sustaining loops or straps which can be engaged without the assistance of an additional person. For example, see U.S. Pat. No. 4,494,599 to Polett and Pat. No. 4,300,608. However, none of the prior art inventions, to applicant's knowledge, appear to have combined this self-sustaining feature with the non-tilt feature disclosed herein.